Ingredients for Bar Soap: Whitening and Exfoliation

Regarding your question about adding Vitamin B3 (Niacinamide) and N-Acetyl-D Glucosamine to bar soap:

Niacinamide and N-Acetyl-D Glucosamine are generally effective in formulations with a pH of 7 or lower. Since most bar soaps have a high pH, typically between 8 and 11, these ingredients are not suitable for use in standard bar soap formulations. At high pH levels, their stability and effectiveness can be compromised.

It's also important to note that rinse-off products like bar soap have limited contact time with the skin. While they can provide some benefits, the results for active ingredients like whitening or exfoliating agents will be significantly less pronounced compared to leave-on products such as serums or creams.

If you are looking for ingredients to add whitening and exfoliating properties to bar soap, consider the following, keeping in mind the limitations of a rinse-off, high-pH environment:

• For Whitening:

  • Kojic Acid Dipalmitate: This is a more stable derivative of Kojic Acid and can be used in formulations with a pH range of 3-9. While typical soap pH is higher, it might offer more stability than other options, though effectiveness in the 8-11 range is still limited. It needs to be dissolved in the oil phase with heat.
  • Kojic Acid: One of the older whitening ingredients. It is water-soluble but can be unstable when dissolved in water. Its effectiveness in a high-pH, rinse-off product may be limited due to stability issues.

• For Exfoliation:

  • Liquid Salicylic Acid (40% Active Salicylic, Cationic For Wash-Off): This form of Salicylic Acid is specifically designed for wash-off products and is water-soluble, making it suitable for incorporation into soap bases as a chemical exfoliant. It works within a pH range of 1-5% (usage rate, not formula pH), but its cationic nature helps it adhere to skin even after rinsing.
  • CelluScrub™ Max: This is a natural cellulose powder that acts as a physical exfoliant. It is insoluble and can be dispersed directly into the soap formula to provide scrubbing action.

For best results with whitening and exfoliating ingredients, leave-on products are generally recommended due to longer contact time with the skin.